The present invention relates to an absorbent article, such as a diaper for the incontinent. Such an article comprises an absorption body, which is enclosed between a liquid-permeable cover layer and a liquid-impermeable cover layer. The absorbent article also has a barrier layer arranged on the outside of the liquid-permeable cover layer, and also elastic members for shaping the absorbent article.
It is previously known to provide a liquid-absorbing article, such as a diaper, with elastic members. The elastic members in this case generally have two main functions. On the one hand, they are used to shape the absorbent article in order to obtain a good fit of the article to a user""s body shape, and, on the other hand, elastic members are used to create different types of leakage barriers. For example, most diapers are provided with elastic members along the side edges, as a result of which elastic and leakage-tight leg bands are obtained when the diaper is placed on the user. It is also possible to create liquid-collecting cups and pockets and raised barriers by arranging elastic members on an absorbent article.
Since diapers with leg elastic, for example of the type described in U.S. Pat. No. 3,860,003, came into general use during the 1970s, a very large number of patent applications concerning elastic for diapers have been filed all around the world.
One problem which is particularly associated with absorbent articles intended for incontinent adults is that of leakage due to large amounts of liquid being passed during a short period of time. It can therefore happen that not all the liquid has time to penetrate into the absorbent article, but instead flows out across the surface of the article and causes leakage. Leakage can also occur in connection with children""s diapers, on account of the fact that a large amount of liquid impacts the article during a short time. A particular concern with babies diapers is the leakage of excrement. Since babies often have very runny excrement, this behaves as a liquid and can easily run out over the edge of the diaper. Such leakage of excrement is particularly unpleasant, and the stains which are left on soiled clothes and bed-linen are very difficult to wash off.
It has therefore been proposed to use elastic members to create liquid-receiving cup-shaped or basin-shaped spaces in absorbent articles. Such a liquid-receiving space serves as a reservoir in which the liquid is held until it has had time to be absorbed into the absorbent article.
Patent Specification SE-C2 502 818 thus describes a liquid-absorbing article intended for disposal after use, such as a diaper, a sanitary towel or the like. The described article has a generally elongate shape and comprises an absorption body and a cover, enclosing the absorption body, with a liquid-permeable inner layer and an outer layer, and also contracting elastic members arranged in connection with at least one layer.
The cover layer on which the elastic members are arranged is connected to the inside or outside of the absorption body. The elastic members extend with an essentially continuously curved portion across an area of the absorption body. By means of the elastic members being adapted to contract, and by means of the fact that they are connected to one of the cover layers, they exert a contracting force on the cover layer in a direction towards the centre of curvature of the elastic members. The contracting force is additionally transmitted to and taken up by the absorption body. For this purpose, the elastic members are arranged with such prestressing that the article is deformed so that a basin wall, essentially transverse to the plane of the article, is formed along the curved elastic portions.
The collection capacity of the liquid-absorbing article described in SE-C2,502,818 has thus been improved compared to similar articles of a more conventional type. This, has been achieved by arranging elastic members which extend with an essentially continuously curved portion across an area of the absorption body, the result of which is that the said elastic members are able to deform the article so that, during use, a cup-like or basin-like collection space is obtained for larger quantities of bodily excreta between the user and the liquid-absorbing article. The basin-like space has essentially no interruptions along the edge which delimits the basin space.
Although such an article, when it is being used, can be given a cup shape that is satisfactory for collecting liquid, this nevertheless requires a specific handling of the article. Thus, the cup shape has to be activated when applying the absorbent article, and it is important here to ensure that a cup really is formed, and not a raised hump, on that side of the article intended to be directed towards the user""s body during use. Obtaining a correct shape of the absorbent article may, however, cause considerable difficulties for certain categories of user, for example people with impaired mobility in their hands or people with poor eyesight. There is therefore a risk of the known article, during use, assuming an incorrect shape which is not favourable for collecting liquid.
A further problem which arises when using absorbent articles is that the bodily fluids collected in the article come into contact with the user""s skin and therefore cause skin irritation. As the absorbent article contains excrement, it may further be desirable to keep the excrement at a distance from the user""s body, since this considerably facilitates the cleaning of the user""s genital region when the article is to be changed.
Patent Specification WO 95/10993 thus already discloses a disposable diaper with an improved ability to keep bodily excreta away from the user""s skin, comprising a sheet which protects the underclothes, a liquid-permeable surface material, an absorbent element placed between the protective sheet and the surface material, and a liquid-impermeable nonwoven covering which has an opening in the crotch area, the edge portions around the opening in the liquid-impermeable nonwoven covering forming sealing flaps around the opening.
For the diaper to be able to absorb bodily excreta more quickly, and to be able to retain this in a more efficient way, WO 95/10993 proposes that the absorbent element has an absorbent layer on which a diffusion layer is arranged, and that the dimensions of the opening in the nonwoven covering are smaller in the longitudinal and transverse directions than the corresponding dimensions of the diffusion layer. The disposable diaper described in WO 95/10993 is stated to comprise elastic means adjacent to the edges of the opening in the nonwoven covering, and along the longitudinal outer edges of the diaper.
Although such a known diaper, when compared to diapers with no nonwoven covering provided with an opening, has an improved ability to hold urine and excrement away from the user""s skin, it is associated with certain disadvantages. For example, there is no guarantee, during use, of a liquid-receiving space forming between the liquid-impermeable nonwoven covering and the liquid-permeable surface material of the diaper. This means that during use of the diaper there is a risk of liquid instead flowing out across the surface of the liquid-impermeable nonwoven covering, with resultant leakage. The risk of such leakage is of course greatest, and has the most obvious consequences, when large amounts of bodily excreta are passed during a relatively short period of time. It can then happen that the small surface area of the liquid-permeable surface material which is exposed by the opening in the liquid-impermeable nonwoven covering is insufficient to be able to absorb the bodily excreta at the ""same rate as these impact the diaper.
Patent publications GB 2 265 550 B, GB 2 265 834 B and GB 2 266 055 A describe disposable diapers, or methods for producing these, in which use is made of an outer layer with an opening, arranged outside a conventional liquid-permeable surface layer on the,inside of the diaper. With the aid of elastic members, sealing flaps are formed in the outer layer, provided with the opening, which flaps are intended to provide a seal around the excretory organs of the user. Patent publication GB 2 265 550 A discloses elastic members which are arranged along and adjacent the edges of the opening in the outer layer, and thus elastizing the peripheri of the opening. Patent specification SE 504 062 C describes an absorbent article having an, elastic member arranged in direct contact with an absorption body. This absorbent article needs manipulation on application.
Despite the fact that strenuous efforts have thus long been made to improve the safety of absorbent articles against leakage, it has not been possible to reach a completely satisfactory solution to the leakage problem. Previously-known absorbent articles therefore only have a limited ability to locally collect and enclose large volumes of, for example, excrement and urine.
An object of the present invention is to provide a disposable liquid-absorbing article which is brought into a highly efficient collecting shape in the position of use. Another object of the invention is to provide a liquid-enclosing space which is created without the article needing to be manipulated on application, and which is retained during use of the absorbent article.
According to the invention, these aims are achieved in a particularly simple way through a combination of two different types of elastic systems which cooperate to produce a completely novel and especially advantageous elastic effect in an absorbent article.
An article designed according to the invention has a longitudinal direction and a transverse direction, a front portion, a rear portion and an intermediate crotch portion, and moreover two side edges extending in the longitudinal direction and two end edges extending in the transverse direction, and it comprises a liquid-permeable cover layer, a liquid-impermeable cover layer, and an absorption body enclosed between the two cover layers, and moreover a barrier layer, with at least one elastic member being arranged with prestressing in direct contact with the absorption body, and extending in an arched curve across the absorption body between the side edges of the article, and moreover that the barrier layer is arranged outside the liquid-permeable cover layer, the barrier layer partly covering the liquid-permeable cover layer and being anchored in the liquid-permeable cover layer only within areas of the barrier layer which are situated adjacent to the edges of the article, and that at least one elastic member is arranged in direct connection with the barrier layer, as a result of which the elastic member cooperates with the elastic member arranged in contact with the absorption body so as to form a constantly basin-shaped space between the barrier layer and the liquid-permeable cover layer.
By means of the invention it is possible to obtain a liquid-receiving space between a barrier layer, arranged across the liquid-permeable cover layer of an absorbent article, and the liquid-permeable cover layer. Elastic members arranged in the barrier layer activate elastic members which are fixed to the absorption body of the article and thereby initiate a shaping of the absorption body, so that the latter curves in the direction away from the barrier layer. In this way, the desired liquid-receiving space is obtained, and retained, without the user needing to manipulate the article prior to use.
A number of different combinations of design patterns of the elastic members can be used, both for the elastic members arranged in the barrier layer and for the elastic members fixed to the absorption body. The elastic members in the barrier layer can be arranged in straight and/or curved paths. In addition, the elastic members can extend in the longitudinal direction and/or transverse direction of the article. At least one elastic member in contact with the absorption body of the article must be arranged in an arch across the absorption body in order to obtain the desired basin-shaped space. It is advantageous, however, to combine two or more such curved elastic members in order to obtain wholly or partially closed basins in the article. For example, a forwardly curved elastic member and a rearwardly curved elastic member can together surround a basin-shaped area in the crotch portion of the article. In a corresponding way, it is possible to obtain a first closed area offset towards the front portion and intended for receiving urine, and a second closed area offset towards the rear and intended for receiving faeces. In addition, one or more curved elastic members can be combined with straight elastic members and with members having other functions. Examples of the latter type of elastic members are those which form leg elastic or waist elastic on diapers.